更改 TextBox 文本时自动更改 DataGrid 中的数据（Xml 源）答案

【问题标题】：Automatically change data in DataGrid when I change TextBox Text (Xml source)更改 TextBox 文本时自动更改 DataGrid 中的数据（Xml 源）
【发布时间】：2020-12-04 00:24:35
【问题描述】：

我对编程很陌生，我正在使用 C# 和 WPF 创建一个小的客户管理应用程序。在我的代码中，我使用DataGrid 来显示来自 XML 文件的数据。我的问题是，当我更改特定单元格的TextBox 文本并且我考虑在TextBox 上使用TextChanged 事件时，我希望DataGrid 中的数据同时更改，但我想不通了解如何管理其余部分。

（代码并不完美，目前并非一切都运行良好）

代码隐藏：

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Xml.Linq;
using System.Xml.Serialization;
using System.Xml;

namespace Kunden2
{
    public partial class MainWindow : Window
    {
        List<Customer> customerlist = new List<Customer>();
        public int RowNumber;

        public MainWindow()
        {
            InitializeComponent();
            if (TextBoxListe.Text.Length != 0)
            {
                ShowList(TextBoxListe.Text + ".xml");
            }

            RowCount();
        }

        //Button Refresh
        private void ButtonRefresh_Click(object sender, RoutedEventArgs e)
        {
            ShowList(TextBoxListe.Text + ".xml");
        }

        //Button Add
        private void ButtonAdd_Click(object sender, RoutedEventArgs e)
        {
            AddPerson();
        }

        //Button Save
        private void ButtonSave_Click(object sender, RoutedEventArgs e)
        {
            SaveXML();
            MessageBox.Show("Erfolgreich gespeichert.");
        }


        //Show List
        private void ShowList(string list)
        {
            if (TextBoxListe.Text.Length != 0)
            {
                if (File.Exists(TextBoxListe.Text + ".xml"))
                {
                    XmlSerializer serial = new XmlSerializer(typeof(List<Customer>));
                    using (FileStream stream = new FileStream(Environment.CurrentDirectory + "/" + list, FileMode.Open, FileAccess.Read))
                    {
                        customerlist = ((List<Customer>)serial.Deserialize(stream));
                    }
                    DataGrid.ItemsSource = customerlist;
                }
                else
                {
                    MessageBox.Show("Datei existiert nicht!");
                }
            }
            else
            {
                MessageBox.Show("Bitte eine Liste eingeben");
            }
            TextBoxNummer.Text = "";
        }


        //Selection to TextBox
        private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            object item = DataGrid.SelectedItem;
            if (item == null)
            {
                TextBoxName.Text = "";
                TextBoxLastName.Text = "";
                TextBoxFirma.Text = "";
                return;
            }

            string Nummer = (DataGrid.SelectedCells[0].Column.GetCellContent(item) as TextBlock).Text;
            string Name = (DataGrid.SelectedCells[1].Column.GetCellContent(item) as TextBlock).Text;
            string NachName = (DataGrid.SelectedCells[2].Column.GetCellContent(item) as TextBlock).Text;
            string Firma = (DataGrid.SelectedCells[3].Column.GetCellContent(item) as TextBlock).Text;

            TextBoxNummer.Text = Nummer;
            TextBoxName.Text = Name;
            TextBoxLastName.Text = NachName;
            TextBoxFirma.Text = Firma;
        }

        //Add Person
        private void AddPerson()
        {
            RowNumber++;
            customerlist.Add(new Customer() { NachName = TextBoxLastName.Text, Name = TextBoxName.Text, Firma = TextBoxFirma.Text, KundenNummer = RowNumber, Aktiv = true });
            updateDataGrid();
            TextBoxNummer.Text = "";
            TextBoxName.Text = string.Empty;
            TextBoxLastName.Text = string.Empty;
            TextBoxFirma.Text = string.Empty;
        }

        //Update Data
        private void updateDataGrid()
        {
            DataGrid.ItemsSource = null;
            DataGrid.ItemsSource = customerlist;
        }

        //Save to XML
        private void SaveXML()
        {
            if (TextBoxName.Text.Length == 0 && TextBoxLastName.Text.Length == 0 && TextBoxFirma.Text.Length == 0)
            {
                XmlSerializer serial = new XmlSerializer(typeof(List<Customer>));
                using (FileStream stream = new FileStream(Environment.CurrentDirectory + "/" + TextBoxListe.Text + ".xml", FileMode.Create, FileAccess.Write))
                {
                    serial.Serialize(stream, customerlist);
                }
            }
            else
            {
                XmlSerializer serial = new XmlSerializer(typeof(List<Customer>));
                using (FileStream stream = new FileStream(Environment.CurrentDirectory + "/" + TextBoxListe.Text + ".xml", FileMode.Create, FileAccess.Write))
                {
                    serial.Serialize(stream, customerlist);
                }
            }
        }

        //Button Delete
        private void ButtonLöschen_Click(object sender, RoutedEventArgs e)
        {
            XmlDocument xdoc = new XmlDocument();
            FileStream up = new FileStream(TextBoxListe.Text + ".xml", FileMode.Open);
            xdoc.Load(up);
            XmlNodeList list = xdoc.GetElementsByTagName("Customer");
            for (int i = 0; i < list.Count; i++)
            {
                XmlElement cu = (XmlElement)xdoc.GetElementsByTagName("Customer")[i];

                if (cu.GetAttribute("KundenNummer") == TextBoxNummer.Text)
                {
                    cu.SetAttribute("Aktiv", "false");

                    break;
                }
            }
            up.Close();
            xdoc.Save(TextBoxListe.Text + ".xml");
            ShowList(TextBoxListe.Text + ".xml");
        }

        private void RowCount()
        {
            RowNumber = customerlist.Count();
        }

        //Button Open
        private void ButtonOpen_Click(object sender, RoutedEventArgs e)
        {
            ShowList(TextBoxListe.Text + ".xml");

        }

        //Text Changed Event
        private void TextBoxName_TextChanged(object sender, TextChangedEventArgs e)
        {
            // What to do here to update the "Name"?
        }
    }
}

XAML

<Window x:Class="Kunden2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Kunden2"
        mc:Ignorable="d"
        Title="Verwaltung" Height="500" Width="800" Background="Gray">

    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <Button x:Name="ButtonAdd" Content="Hinzufügen" Grid.Row="3" Margin="16,28,30,47" Click="ButtonAdd_Click" Grid.Column="2"/>
        <Button x:Name="ButtonSave" Content="Speichern" Grid.Row="3" Grid.Column="1" Margin="22,28,18,47" Click="ButtonSave_Click"/>
        <Button x:Name="ButtonRefresh"  Content="Neu Laden" Grid.Column="1" Grid.Row="2" Margin="22,46,18,29" Click="ButtonRefresh_Click"/>
        <Button x:Name="ButtonDelete"  Content="Löschen" Grid.Row="2" Grid.Column="2" Margin="10,46,30,29" Click="ButtonLöschen_Click"/>
        <TextBox x:Name="TextBoxName"  Grid.Row="1" Grid.Column="1" TextChanged="TextBoxName_TextChanged" Margin="52,27,48,63"/>
        <TextBox x:Name="TextBoxLastName" Grid.Row="1" Grid.Column="2" Margin="50,27,50,63"/>
        <TextBox x:Name="TextBoxFirma" Grid.Row="1" Grid.Column="1" Margin="52,90,48,0"/>
        <TextBox x:Name="TextBoxNummer" Grid.Row="1" Grid.Column="2" Margin="50,90,50,0" IsReadOnly="True" />
        <TextBlock Text="Vorname:" Grid.Row="1" Grid.Column="2" FontSize="20" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="87,0,94,90"/>
        <TextBlock Text="Name:" Grid.Row="1" Grid.Column="1" FontSize="20" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="97,0,110,90" RenderTransformOrigin="0.479,0.03"/>
        <TextBlock Text="Firma" Grid.Row="1" Grid.Column="1" FontSize="20" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="0,63,110,27"/>
        <TextBlock Text="Nummer" Grid.Row="1" FontSize="20" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="0,63,94,27" Grid.Column="2"/>

        <DataGrid x:Name="DataGrid" Grid.RowSpan="4" Grid.ColumnSpan="2" IsReadOnly="True" SelectionChanged="DataGrid_SelectionChanged"  SelectionMode="Single" SelectionUnit="FullRow"  AutoGenerateColumns="False" Margin="5,5,247,5" >
            <DataGrid.Columns>
                <DataGridTextColumn Header="Nr." Binding="{Binding KundenNummer}"/>
                <DataGridTextColumn Header="Vorname" Binding="{Binding Name}"/>
                <DataGridTextColumn Header="Name" Binding="{Binding NachName}"/>
                <DataGridTextColumn Header="Firma" Binding="{Binding Firma}"/>
                <DataGridTextColumn Header="Aktiv" Binding="{Binding Aktiv}"/>
            </DataGrid.Columns>
        </DataGrid>
        <TextBox x:Name="TextBoxListe" Grid.Column="1" Margin="52,67,48,24"/>
        <TextBlock Text="Liste:" Grid.Column="1" FontSize="20" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="110,40,110,51"/>
        <Button x:Name="ButtonOpen"  Content="Öffnen" Grid.Column="2" Margin="16,52,30,24" Click="ButtonOpen_Click"/>
    </Grid>
</Window>

客户类别

namespace Kunden2
{
    public class Customer
    {
        [XmlAttribute]
        public bool Aktiv { get; set; }

        [XmlAttribute]
        public int KundenNummer { get; set; }

        [XmlElement]
        public string Name { get; set; }

        public string NachName { get; set; }

        public string Firma { get; set; }
    }
}

【问题讨论】：

标签： c# xml wpf

【解决方案1】：

由于您使用的是纯代码隐藏，我将向您展示一个解决方案，尽管我建议您熟悉 MVVM 设计模式，它可以让您免于通过绑定进行大量事件处理，并允许一个干净的表示与您的逻辑和数据分离。

要更新文本更改事件处理程序中的数据，您需要访问DataGrid 中的SelectedItem，并将其对应属性设置为关联TextBox 的Text。

private void TextBoxName_TextChanged(object sender, TextChangedEventArgs e)
{
   if (DataGrid.SelectedItem is Customer customer)
      customer.Name = ((TextBox)sender).Text;
}

但是，此更改尚未反映在用户界面中，因为您的 Customer 模型未实现 INotifyPropertyChanged。您可以像下面那样为您的所有属性实现它。它的作用是在属性被修改时引发PropertyChanged 事件，以表明控件必须更新其绑定以获取更改的值。

public class Customer : INotifyPropertyChanged
{
   private string _name;
   public string Name
   {
      get => _name;
      set
      {
         if (_name != value)
         {
            _name = value;
            OnPropertyChanged();
         }
      }
   }

   // ...your other properties.

   public event PropertyChangedEventHandler PropertyChanged;

   protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
   {
      PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
   }
}

【讨论】：

谢谢您的遮阳篷。它对我来说效果很好。